Expansion assembly and hot water tank

ABSTRACT

An expansion assembly for use in a hot water device, having a water container for receiving water to be heated, includes an expansion tank with a lower expansion tank half shell and an upper expansion tank half shell. The lower expansion tank half shell has a coupling portion for coupling to the water container of the hot water device. The upper expansion tank half shell is configured to be coupled to a cold water feed line. The upper expansion tank half shell and the lower expansion tank half shell are hermetically connected at circumferential edges forming the expansion tank.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Phase of PCT Application No.PCT/EP2021/079971 filed Oct. 28, 2021, which claims priority to GermanPatent Application No. 102020134297.7 filed Dec. 18, 2020, thedisclosure of which is hereby incorporated in its entirety by referenceherein.

TECHNICAL FIELD

The present invention relates to an expansion assembly and an associatedhot water tank.

BACKGROUND

Hot water tanks for domestic use have been generally known.

For example, EP 2 827 077 discloses a water container for receivingwater to be heated and an inelastic expansion tank for receiving anamount of water which is provided at the tap stop in a fitting connectedto the outlet, and for receiving an amount of water which corresponds toan amount of expansion when the cold water in the water container isbeing heated. The expansion tank is hermetically closed to an outerenvironment of the hot water tank and is in fluid communication with afeed line sided water jet pump such that the water jet pump allows for anegative pressure to be created in the expansion tank.

SUMMARY

Hermetic expansion tanks have several disadvantages, e.g., it isdifficult to provide for safe and reliable emptying of the expansiontank. Disclosed herein and discussed in detail below are hot water tankshaving improved expansion assemblies.

According to one or more embodiments, an expansion assembly for use in ahot water device is disclosed, in particular in a hot water tank fordomestic use, wherein the hot water device has a water container forreceiving water to be heated, wherein the expansion assembly comprisesan expansion tank, the expansion tank comprises a lower expansion tankhalf shell and an upper expansion tank half shell, the lower expansiontank half shell has a coupling portion for coupling to the watercontainer of the hot water tank, the upper expansion tank half shell isconfigured to be coupled to a cold water feed line, and the upperexpansion tank half shell and the lower expansion tank half shell areconnected hermetically at circumferential edges, forming the expansiontank.

The upper expansion tank half shell and the lower expansion tank halfshell may each have a circumferential friction welding edge to create avibration friction welding connection of the upper expansion tank halfshell and the lower expansion tank half shell.

The expansion assembly may be embodied by the functional integration ofthe coupling portion with the lower expansion tank half shell to bedirectly mounted onto the water container or storage tank. Hence, thereis no need for an additional coupling piece, making a reduction of thenumber of parts possible. In its simplest configuration, the expansionassembly consists of two tank half shells, which may be produced byinjection molding.

In an alternative configuration of the connection of the expansion tankhalf shells, the invention also allows for a further simplification andreduction of the number of parts by the functional integration of theseat emptying component into the expansion tank.

For example, a seat for an emptying component, e.g., a nozzle of a waterjet pump, is integrated with the lower and/or the upper expansion tankhalf shell, wherein the nozzle of the water jet pump is fixed betweenthe connected expansion tank half shells.

The emptying component allows for a negative pressure to be createdwithin the expansion tank by the water jet of the water flowing into thehot water tank, which negative pressure then results in the emptying ofthe contents of the expansion tank into the hot water tank.

The expansion assembly may further include an emptying component, theemptying component having a nozzle for sucking expansion water off theexpansion tank.

The venturi nozzle may have a parabolically tapering cross-sectionalshape. This cross-sectional shape results in a linearly narrowingcross-sectional area. Thus, the increase of the flow rate inside theventuri nozzle is achieved with a particularly low loss of pressure.

The nozzle may be comprised of a different material than the material ofthe expansion tank, e.g., brass and/or bronze.

Brass and bronze may have an increased cavitation resistance.

Alternatively, the nozzle may be formed integrally with, and integratedinto, the upper expansion tank half shell or the lower expansion tankhalf shell. In other words, the nozzle is then appropriately formed ontothe tank half shell.

The upper expansion tank half shell and the lower expansion tank halfshell may be embodied as easily demoldable plastics parts. Here, easilydeformable means that the number of undercuts, and the complexity of theparts, are as low as possible.

In one or more embodiments, an opening between the emptying componentand the expansion tank is sealed by a sealing unit which, may include aball resting on a sealing element when the expansion tank is empty suchthat a negative pressure within the expansion tank is prevented.

In addition to the negative pressure, the introduction of air from theexpansion tank into the storage tank is avoided. The sealing unit mayhave a ball and a vertical guide for guiding the ball onto the sealingelement and away from the same, respectively.

In one or more embodiments, the expansion assembly further comprises aventing component, wherein the venting component is arranged at theupper expansion tank half shell and allows for air to be exchangedbetween expansion tank and atmosphere.

Thereby, a damaging negative pressure within the expansion tank can beprevented.

The venting component may have a blocking element, e.g., a swellingdisk, wherein the blocking element is configured to prevent water fromleaking out of the expansion tank via the venting component.

The blocking element may also be a further check valve such as a ballvalve.

In case of failure, i.e., when water from the venting component isleaking out of the hot water tank, the blocking element can block thewater leakage. This does impede the drip protection function, yet thedripping fitting is also signaling the user that the hot water tank isnot working optimally. Thus, the user is able to detect the case offailure quickly.

In another aspect, an expansion assembly for use in a hot water device,in particular in a hot water tank for domestic use, is suggested,wherein the hot water device has a water container for receiving waterto be heated, wherein the expansion assembly comprises an expansion tankand a venting component, wherein the venting component allows for air tobe exchanged between expansion tank and atmosphere. The ventingcomponent has a blocking element, e.g., a swelling disk, wherein theblocking element is configured to prevent water from leaking out of theexpansion tank via the venting component.

No matter how the tank is implemented, the venting component offers theadvantages explained in the above embodiments in combination with theexpansion tank formed by two expansion tank half shells.

In another aspect, a hot water tank, such as for domestic use, maycomprise a storage tank, a cold water feed line for connection to awater supply network, a hot water outlet for providing hot water at afitting connectable thereto, and an expansion assembly according to theinvention.

The hot water tank according to the invention may be combined with allof the embodiments of the expansion assembly described above whileoffering the same advantages.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically shows an exemplary hot water tank,

FIG. 2 schematically shows the exemplary hot water tank without ahousing for illustrative purposes,

FIG. 3 schematically shows the exemplary hot water tank of FIG. 2 incross-sectional view,

FIG. 4 schematically shows an exemplary hot water tank in detailed view,

FIG. 5 schematically shows an exemplary hot water tank in sectionalview,

FIG. 6 schematically shows an exemplary hot water tank in sectionalview,

FIG. 7 schematically shows an exemplary hot water tank in sectionalview,

FIG. 8 schematically shows an exemplary hot water tank in sectionalview,

FIG. 9 schematically shows an exemplary hot water tank in exploded view,

FIG. 10 schematically shows an exemplary hot water tank in explodedview,

FIG. 11 schematically shows an exemplary hot water tank in sectionalview,

FIG. 12 schematically shows an exemplary hot water tank in sectionalview, and

FIG. 13 schematically shows an exemplary hot water tank in sectionalview.

DETAILED DESCRIPTION

FIG. 1 shows a hot water tank 1 in perspective view. The storage tank isarranged within a housing composed of two housing half shells 2, 3 andis enclosed by a thermal insulation. In the storage tank, there isdrinking water which is usually heated to a desired temperature by anelectric heating element to be provided at a tap as hot water.

At the front side, an operating element 4 is arranged which serves toadjust the temperature of the water in the storage tank.

At its top side, the hot water tank 1 has a cold water connection 6 anda hot water connection 8. Cold water is introduced into the storage tankvia the cold water connection 6 and, via the hot water connection 8, theheated water flows to the tap.

The hot water tank 1 is usually not pressurized during operation, i.e.,the pressure within the storage tank is simply atmospheric pressure andnot a line pressure usual for a water line. This means that a tappingprocess is introduced by opening a valve or the like provided in thepipe section connected to the cold water connection 6. Due to a thenpositive pressure at the cold water connection 6, the inflowing coldwater pushes the heated water out of the hot water connection 8.

Further, a venting assembly 80 is arranged at the top side. The ventingassembly 80 is in fluid communication with an expansion assembly 70which will be described in more detail with reference to the followingfigures. The venting assembly 80 allows for permanent negative pressureto be prevented inside the storage tank, and, in particular, in anexpansion tank connected thereto, which might damage or destroy the hotwater tank 1. Moreover, the venting group 80 is adapted to preventleakage of liquids, i.e., water, from within the storage tank, as willbe described in more detail in the following as well.

FIG. 2 shows the exemplary hot water tank 1 without insulation andhousing half shells 2, 3 in schematic view (compare FIG. 1 ). Theexpansion assembly 70 is shown at a top side of the proper storage tank10. In particular, it comprises an expansion tank composed of an upperexpansion tank half shell 72 and a lower expansion tank half shell 74.

Preferably, the lower half shells of the expansion tank are connected byvibration friction welding. To this end, the upper expansion tank halfshell 72 and the lower expansion tank half shell 74 have circumferentialfriction welding edges 73, 75. The friction welding edges 73, 75 areconfigured to be accessed via an appropriate machine. Vibration frictionwelding provides for a particularly cost effective and reliable,permanent connection between the two half shells. It is also possible toconnect second half shells differently.

FIG. 3 shows the exemplary hot water tank 1 of FIGS. 1 and 2 inschematic cross-sectional view so that a heating element 12 arrangedinside the storage tank 10 as well as a temperature sensor 16 arevisible.

The heating element 12 embodied as electric heating element with aplurality of coils is only exemplary, other variants for heating thewater within the storage tank 10 are also conceivable. The heatingelement 12 is electrically connected to a power supply via connections13 and 14 formed on top of, and outside of, the storage tank.

The temperature sensor 16 exemplarily embodied as integral temperaturesensor is likewise connected to a control electronics via a connection17.

For the sake of simplicity, the control electronics are not shown in anyof the figures, with the configuration necessary for controlling and/orregulating a hot water tank 1 being known to the person skilled in theart.

As shown, a cold water pipe 20 in fluid communication with the coldwater inlet 6 has its opening 22 in the lower region of the storage tank10. Thus, when a tap at a fitting (not shown) is being operated, coldwater flows into the bottom region of the storage tank 10, is heated bythe heating element 12 and exits the storage tank 10 via an opening 32of the hot water pipe 30 arranged in the upper region of the storagetank.

FIG. 4 shows the exemplary expansion assembly 70 of FIG. 3 in schematicenlarged view. The cold water feed line 6 and the venting assembly areconnected to the expansion assembly 70, while the hot water pipe 30 tothe hot water connection 8 bypasses the expansion assembly 70 in arecess. Thus, an undesirable heat transfer from the hot water pipe 30 tothe inside of the expansion tank can be prevented.

A connection portion 76 of the lower expansion tank half shell 74 canalso be seen. This connection portion 76 may be formed integrally withthe lower expansion tank half shell 74 and is provided for connection toa corresponding connection portion 18 (compare FIG. 12 ) of the storagetank 10. The cold water pipe 20 is mounted to the connection portion 18inside the storage tank.

In the following FIGS. 5 to 7 , sections along planes A-A (FIG. 5 ), B-B(FIG. 6 ) and C-C (FIG. 7 ) are shown so that the interior components ofthe expansion assembly 70 can be seen.

Cover caps 42, 44, 46 are provided at the top side of the housing of thehot water tank for covering purposes. Further, a plurality of clips 48a-48 d and gaskets 50 a-50 i are provided for mounting and sealingpurposes. The gaskets may be O-ring gaskets.

Different pipe sections 62, 30 and 82 have flanges 63, 33, 83 and 84 toprovide for a safe attachment of the further components of the pipesections 62, 30 and 82 in longitudinal direction.

A sieve 64 is arranged in the cold water connection 6 to preventcontaminations included in the water such as limestone fragments fromentering into the storage tank 10.

The cold water connection 6 is coupled to the pipe section 62 via acoupling 66. Before the cold water enters into the storage tank 10 viathe cold water pipe 20, it flows through an emptying component 90 whichis configured to suck the contents off the expansion tank if anyexpansion water is present therein.

To this end, a venturi nozzle 92 is provided which results in across-sectional tapering to increase flow rate. The venturi nozzle 92may be made of a metallic material, e.g., copper, and may be clampedbetween the upper expansion tank half shell 72 and the lower expansiontank half shell 74 in a seat 76 provided therefor. Thus, the particularingenious configuration of the expansion tank allows for the functionalintegration of the emptying component.

While the venturi nozzle 92 is configured as separate metal part in thisembodiment, the cross-sectional tapering may also be integrated directlywith the expansion tank half shell, such as the upper expansion tankhalf shell 72, with no undercuts or the like making its demoldingdifficult.

After having exited the venturi nozzle 92, the cross-section becomeslarger again before the water enters into the storage tank 10.

When water is flowing in, the venturi nozzle 92 provides for sucking ofwater off the expansion tank via an opening 100, which is particularlywell shown in FIG. 7 .

The opening 100 connects the venturi nozzle 92 to a sealing portion 98on which a ball 96 rests sealingly when all of the water has been suckedoff the expansion tank. The ball 96 has a small density so that itfloats when water is flowing in and does not rest on the sealing portion98 any longer. Thus, the water in the connection can again be sucked offthe expansion tank via the venturi nozzle 92. A guiding element 94 whichis open towards the expansion tank restricts the movement of the ball 96to be substantially in vertical direction.

An arrangement similar to the one of the emptying component 90 isprovided in the region of the venting assembly 80. Here, also a ball 86is guided along a guiding element 95 in vertical direction, depending ona water level in the expansion tank. When a certain level has beenreached, the ball 86 seals to a sealing portion 88 so that no water canexit the hot water tank 1 from the venting opening.

FIG. 8 shows a further section along plane A-A without the hot waterpipe 30 and further pipes. In this section, elements 78 for introducingand fixing the clips are shown at the upper end of the upper expansiontank half shell 72.

FIGS. 9 and 10 show exploded views of the expansion assembly 70, withFIG. 10 additionally showing a cross-section along plane A-A.

In addition to section B-B shown in FIG. 6 , a further section isdepicted in FIG. 11 lying between section A-A and section B-B. Here, theopening 100 can be provided between the sealing portion 98 and theventuri nozzle 92.

FIG. 12 shows a perspective cross-sectional view similar to the viewshown in FIG. 4 but with one section further backwards in the referenceplane across the venturi nozzle 92.

Further shown are the connection of the connecting portion 76 of thelower expansion tank half shell 74 to the corresponding connectingportion 18 of the storage tank 10 as well as the connection of the hotwater pipe 30 to a corresponding connecting portion 19 at the storagetank 19 which also forms the hot water connection 32.

In addition, a venting cap 81 can be seen in this view which forms onepart of the venting assembly 80 and is adapted to ensure the closing ofthe venting opening when water is leaking. To this end, the venting cap81 may preferably have at least one swelling disk. When the at least oneswelling disk comes into contact with water, it swells such that theventing opening will be closed reliably.

Then, a user will detect the malfunction of the hot water tank 1 given adripping fitting, e.g., since no expansion water, and also no drippingwater in the fitting, can be received in the expansion tank when theswelling disk closes the venting opening.

FIG. 13 shows an exemplary schematic detailed view of the upper storagetank portion as well as the expansion assembly 70 in the cross-sectionalview of FIG. 12 .

LIST OF REFERENCE SIGNS

-   -   1 hot water tank    -   2, 3 housing half shell    -   4 operating element    -   6 cold water connection    -   8 hot water connection    -   10 storage tank    -   12 heating element    -   13, 14 connections of the heating element    -   16 temperature sensor    -   17 connection of the temperature sensor    -   18, 19 connecting portion    -   20 cold water pipe    -   22 opening of the cold water pipe    -   30 hot water pipe    -   32 opening of the hot water pipe    -   33 flange    -   42, 44, 46 cover cap    -   48 a,b,c,d clip    -   50 a,b,c,d,e,f,g,h,i gasket    -   62 pipe section    -   63 flange    -   64 sieve    -   66 coupling    -   70 expansion assembly    -   72 upper expansion tank half shell    -   73 circumferential friction welding edge    -   74 lower expansion tank half shell    -   75 circumferential friction welding edge    -   76 seat    -   78 elements    -   80 venting assembly    -   81 venting cap    -   82 pipe section    -   83 flange    -   84 flange    -   85 guiding element    -   86 ball    -   88 sealing portion    -   90 emptying component    -   92 venturi nozzle    -   94 guiding element    -   96 ball    -   98 sealing portion    -   100 opening

1. An expansion assembly for use in a hot water device having a watercontainer for receiving water to be heated, the expansion assemblycomprising: an expansion tank including a lower expansion tank halfshell and an upper expansion tank half shell; wherein the lowerexpansion tank half shell has a coupling portion configured to couple tothe water container of the hot water device, upper expansion tank halfshell is configured to be coupled to a cold water feed line, and theupper expansion tank half shell and the lower expansion tank half shellare connected hermetically at circumferential edges, forming theexpansion tank.
 2. The expansion assembly according to claim 1, whereinthe upper expansion tank half shell and the lower expansion tank halfshell each have a circumferential friction welding edge to create avibration friction welding connection of the upper expansion tank halfshell and the lower expansion tank half shell.
 3. The expansion assemblyaccording to claim 1, wherein the lower and/or the upper expansion tankhalf shell include a seat for a nozzle of a water jet pump, wherein thewater jet pump is formed between the connected expansion tank halfshells.
 4. The expansion assembly according to claim 1, furthercomprising an emptying component having a venturi nozzle configured todrain expansion water from the expansion tank.
 5. The expansion assemblyaccording to claim 4, wherein the nozzle has a parabolically taperingcross-sectional shape.
 6. The expansion assembly according to claim 4,wherein the nozzle is comprised of a different material than thematerial of the expansion tank.
 7. The expansion assembly according toclaim 4, wherein the nozzle is formed integrally with, and integratedinto, the upper expansion tank half shell, or the lower expansion tankhalf shell.
 8. The expansion assembly according to claim 1, wherein theupper expansion tank half shell and the lower expansion tank half shellare embodied as easily demoldable plastics parts.
 9. The expansionassembly according to claim 4, wherein an opening between the emptyingcomponent and the expansion tank is sealed by a sealing unit thatincludes a ball resting on a sealing element when the expansion tank isempty such that a negative pressure within the expansion tank isprevented.
 10. The expansion assembly according to claim 9, wherein thesealing unit has a second ball and a vertical guide for guiding thesecond ball onto the sealing element and away from the same,respectively.
 11. The expansion assembly according to claim 1 furthercomprising a venting component arranged at the upper expansion tank halfshell and configured to allow air to be exchanged between the expansiontank and the atmosphere.
 12. The expansion assembly according to claim11, wherein the venting component has a blocking element configured toprevent water from leaking out of the expansion tank via the ventingcomponent.
 13. (canceled)
 14. The expansion assembly according to claim12, wherein the blocking element is a swelling disk.
 15. The expansionassembly according to claim 1 further comprising an emptying component.16. The expansion assembly according to claim 15, wherein the lowerand/or the upper expansion tank half shell include a seat for theemptying component, wherein the seat is formed between the expansiontank half shells.
 17. A hot water tank comprising: a storage tank; acold water feed line coupled to the storage tank and configured toconnect to a water supply network; a hot water outlet coupled to thestorage tank and configured to provide hot water at a fittingconnectable thereto; and an expansion assembly including an expansiontank having a lower expansion tank half shell and an upper expansiontank half shell, wherein the lower expansion tank half shell has acoupling portion configured to couple to the water container of the hotwater device, wherein the upper expansion tank half shell is configuredto be coupled to a cold water feed line, and wherein the upper expansiontank half shell and the lower expansion tank half shell are connectedhermetically at circumferential edges, forming the expansion tank. 18.The hot water tank according to claim 17, wherein the upper expansiontank half shell and the lower expansion tank half shell each have acircumferential friction welding edge to create a vibration frictionwelding connection of the upper expansion tank half shell and the lowerexpansion tank half shell.
 19. The hot water tank according to claim 17,wherein the lower and/or the upper expansion tank half shell include aseat for a nozzle of a water jet pump, wherein the water jet pump isformed between the connected expansion tank half shells.
 20. The hotwater tank according to claim 17, wherein the expansion assembly furtherincludes a venting component arranged at the upper expansion tank halfshell and configured to allow air to be exchanged between the expansiontank and the atmosphere.